#include<stdio.h>
#include<math.h>
int main(){
	int a,b,c,perimeter;
	double area,s;
	
	scanf("%d%d%d",&a,&b,&c);
	
	perimeter = a + b + c;
	
	if(a + b > c && a + c > b && b + c > a){
		s = (a + b + c) / 2.0;
		area = sqrt(s * (s - a) * (s - b) * (s - c));
		printf("area = %.2lf; perimeter = %.2lf",area,(double)perimeter);
	}else{
		printf("These sides do not correspond to a valid triangle");	
	}
	return 0;
}
